1. Field
The present disclosure relates to a vehicle brake system.
2. Description of the Related Art
Japanese Unexamined Patent Application Publication No. 2012-001091 describes a vehicle brake control device (vehicle brake system). When a collision of the vehicle has been detected by collision detection sensors, the vehicle brake control device automatically actuates a brake controller (actuates automatic braking) in accordance with a vehicle speed detected by a speed sensor. The vehicle is then braked automatically after a collision by the thus configured brake control device.
The brake control device described in Japanese Unexamined Patent Application Publication No. 2012-001091 actuates the brake controller (actuates automatic braking) when a collision of the vehicle has been detected.
As long as electrical power is being supplied to electrical components such as sensors, the brake control device actuates the brake controller when a collision has been detected, even if the engine of the vehicle is in a stopped state, such as when the ignition is off, or during an idling stop or engine stall. For example, the brake control device actuates the brake controller when another vehicle collides with the vehicle while the vehicle is stopped.
However, when the engine is stopped, since the vehicle is stationary, the vehicle speed is not that high even if the vehicle starts to move due to, for example, the collision. Thus, the vehicle is sufficiently braked even if the braking force generated by actuation of the brake controller is small.
For an electrical brake controller, the electrical power consumption of the brake controller is suppressed when a small braking force is generated, enabling exhaustion of electrical power stored in a storage device (such as a battery) to be suppressed by reducing the braking force generated by the brake controller.
Electricity is not being generated by the alternator when the engine has stopped, and sometimes problems occur if the stored electrical power has been exhausted, such as when the engine is restarted. When the engine is stopped, it is accordingly desirable to suppress, by as much as possible, the stored electrical power from being exhausted by the brake controller.
Moreover, in a stopped state of the engine, if a collision with the vehicle has occurred and, furthermore, the brake controller is actuated and a large braking force is generated, occupants of the vehicle, such as the driver, receive a double collision impact, both when the collision with the vehicle occurs, and also when the vehicle is braked by the braking force. Sometimes the driver, for example, is in a relaxed posture in a vehicle with a stopped engine. Thus the driver, for example, receives a double impact while in an unstable posture, and is liable to be greatly affected by the impacts.
Due to the above, it is accordingly preferable for the braking force generated by actuating a brake controller to be small in cases in which a collision of a vehicle has been detected while the engine is in a stopped state.